1. Field of Invention
The present disclosure of invention relates to liquid crystal display (LCD) panels such as employed in an LCD monitor.
2. Description of the Related Technology
A liquid crystal display (LCD) device displays an image by controlling light transmittance according to voltages applied across a liquid crystal layer where the latter is interposed between two substrates.
In LCD devices, light is transmitted toward a direction in which the light is not shielded (blocked) by liquid crystal molecules of the liquid crystal layer. Since the realized image is dependant on angle of light transmission, the useful viewing angles of the LCD device are generally narrower than those of other types of displays. A so-called vertical alignment (VA) mode LCD device has been developed in order to try to realize wider viewing angles.
The VA mode LCD device includes a liquid crystal layer that exhibits a negative type dielectric constant anisotropy. The liquid crystal layer is sealed between two substrates that have undergone a vertical alignment process. The liquid crystal molecules of the liquid crystal layer have homotropic alignment characteristics. During operation, when a voltage is not applied to two substrates, molecules in the liquid crystal layer automatically aligns in a vertical direction with respect to a surface of a substrate so as to block light transmission and thereby display a black pixel. When a predetermined voltage is applied across the two substrates, molecules in the liquid crystal layer align in a horizontal direction with respect to the surface of the substrate so as to transmit light and thus display a white or fully lit pixel. When a voltage that is less than the predetermined voltage is applied to two substrates, molecules in the liquid crystal layer align in an inclined direction with respect to the surface of the substrate to thereby display a gray pixel.
The LCD device generally has a disadvantage of a narrow viewing angle. In order to overcome the disadvantage, a patterned vertical alignment (PVA) mode and a super patterned vertical alignment (SPVA) mode have been proposed wherein each pixel is subdivided into multiple domains and different voltages drive the respective multiple domains. The PVA mode is a technology in which a common electrode formed on an upper substrate and a pixel electrode formed on a lower substrate are patterned to realize multiple domains. The SPVA mode is a technology in which one pixel is divided into a plurality of sub-pixels to apply different pixel voltages to the divided sub-pixels in response to a single applied voltage. As an example of the SPVA mode, a coupling capacitor (CC-SPVA) is used to apply a different pixel voltage to the sub-pixel that is driven via the coupling capacitor as opposed to the sub-pixel that is directly driven.
In other words, in a CC-SPVA mode LCD device, a first sub-pixel directly receives a pixel voltage supplied from a data line, and a second sub-pixel receives a smaller voltage due to voltage division provided by the coupling capacitor. While viewing angle may be widened when the CC-SPVA mode LCD device is employed in a product, the product may have disadvantages such as low overall light transmittance and the generation of afterimages.